The audio frequency range is accepted by many to be about 20 Hz (Hertz) to 20 kHz (kilohertz), although some people are able to hear sounds above and below this range. Also, a bass frequency range is accepted by many to be about 16 Hz to 512 Hz. It may be relatively difficult for a person to detect which direction a bass frequency sound is coming from because the wavelength associated with bass frequency sound is larger than the distance between a person's ears (usually less than 1 ft (foot)). For example, assuming that the speed of sound is 340 m/s, the wavelength associated with a frequency of 100 Hz is about 11 ft. As a result, recording engineers have conventionally mixed bass frequencies as monophonic (mono).